Tribology of flexible seals for reciprocating motion

The dynamic behavior of oil films formed between a band-shaped nitrile rubber specimen with a D-shaped or lip-shaped cross section and an oscillating glass plate is directly observed by means of the mono-chromatic optical interferometry technique. The friction force is also measured. The effects of he cross sectional shape of the seal and the length of the stroke on the film formation and friction characteristics are discussed together with the effects of surface defects. On the basis of analyses of experimental data, the conditions which bring about the film collapse are clarified. It is also claimed that the distinction of lubrication modes by the Stribeck curve might be reconsidered. [S0742-4787(00)02304-3].